Removable handle for a rotary oral-dental instrument, and oral-dental instrument comprising such a handle

Abstract

The present invention relates to a handle (1) for an oral-dental instrument, which handle has an elongate outer shape along a longitudinal axis (100) enabling it to be removably held and to be rotated by an instrument-holding apparatus, said handle having an inner recess (120), one of the ends of which is open, for receiving a portion of an oral-dental instrument blade. According to the invention, this handle (1) comprises at least two movable elements that surround the inner recess (120) and are movable with respect to each other between a first configuration, referred to as the closed configuration, and a second configuration, referred to as the open configuration, the inner recess (120) having a different shape in the first configuration and the second configuration. The invention also relates to an oral-dental instrument comprising a blade held in such a handle (1).

Description

Removable handle for a rotary oral instrument, and oral instrument comprising such a handle Field of invention

[0001] The present invention relates to oral-dental instruments.

[0002] In particular, the invention relates to oral-dental instruments intended to be removably held by instrument-holding equipment and driven in rotation by this instrument-holding equipment. Prior art

[0003] Among the oral-dental instruments used by dental practitioners, some instruments are rotary. These instruments are intended to be carried by an instrument-holding device capable of rotating them around an axis corresponding to the longitudinal axis of the instrument.

[0004] Instrument-holding equipment is a tool intended to be held by the dental practitioner, which generally comprises motorization means, for example an electric or pneumatic motor, and an instrument-holding equipment head, having an opening in which an oral-dental instrument can be fixed. The motorization means are capable of driving the instrument in rotation, this rotation being able to be continuous, alternating, or even an alternating rotational movement of low amplitude providing a vibratory effect.

[0005] Rotary oral instruments generally comprise an active portion, which is the portion of the instrument that is intended to perform work on or in the teeth or mouth of the patient, and a portion that is intended to be inserted into the instrument-holding equipment head to be removably held therein. In certain rotary oral instruments, this portion of the instrument intended to be inserted into the instrument-holding equipment head is constituted by a handle, and the active portion of the instrument is constituted by a blade fixed to this handle. The present invention is particularly applicable to this type of oral instruments.

[0006] Such a handle often has a standardized shape and dimensions, making it compatible with the head of the instrument-holding equipment that is intended to accommodate it. Thus, the external shape of this handle is generally inscribed in a cylindrical envelope and has, near one of its ends, a flat and a peripheral groove that allow it to be properly held and rotated by the instrument-holding equipment. Such handles most often have standardized characteristics and dimensions, for example corresponding to “Type 1” handles as defined by the EN ISO 1797 standard concerning rotary oral-dental instruments.

[0007] At its second end, the handle carries the blade of the instrument, which generally extends coaxially with the axis of the handle. This blade generally comprises two portions: a non-active portion, which is often generally cylindrical in shape and is assembled to the handle, and an active portion, which forms the free end of the blade. This active portion, which is intended to perform work on or in the patient's teeth or mouth, is often machined to have sharp or abrasive edges.

[0008] The blade is generally joined to the handle by inserting the end of the non-active portion of the blade into an internal housing provided in the second end of the handle. This non-active portion of the blade is then fixed in the handle, for example by a tight fit, by crimping or by gluing.

[0009] Among the oral instruments consisting of a handle and a blade attached to this handle, we know in particular many endodontic instruments. Endodontic instruments are rotating oral instruments intended to be introduced into the root canal of a tooth by a dental practitioner, as part of endodontic care, to empty, clean and shape this root canal, before filling it.

[0010] The manufacturing cost of endodontic instruments is generally relatively high. Since such instruments are susceptible to fatigue failure, they can only withstand a limited number of uses and are often single-use. They therefore represent a significant source of expense for dental practitioners.

[0011] For manufacturers of such endodontic instruments, manufacturing is generally carried out in two stages. First, the blade is machined and shaped. Second, this blade is assembled with the handle. This assembly step requires specialized tooling and several operations that are often carried out manually. Furthermore, the manufacture of the handle itself, often made of copper alloys that can be plated with nickel and gold, is relatively expensive. The handle and its assembly to the blade therefore represent a significant part of the manufacturing cost of the endodontic instrument.

[0012] Generally speaking, this structure of oral-dental instruments with a blade assembled to a handle implies relatively high production costs of these instruments. Objectives of the invention

[0013] The present invention aims to overcome these drawbacks of the prior art.

[0014] In particular, the present invention aims to enable a reduction in the manufacturing costs of rotary oral-dental instruments. Its particular objective is to reduce the number of manual interventions and specific machines used for the manufacturing and assembly of such instruments.

[0015] Another particular objective of the invention is to provide rotary oral-dental instruments of reduced cost, which remain compatible with the instrument-holding equipment with which dental practitioners are usually equipped.

[0016] These objectives, as well as others which will appear more clearly subsequently, are achieved using a handle for an oral-dental instrument, having an external shape elongated along a longitudinal axis, making it suitable for being removably held by an instrument-holding device and driven in rotation, around the longitudinal axis, by the instrument-holding device, this handle having a first end, and a second end opposite the first end, this handle having an internal housing, open at the second end and extending along the longitudinal axis, this internal housing being suitable for receiving a portion of a blade of the oral-dental instrument.According to the invention, this handle comprises at least two movable elements surrounding the internal housing, the movable elements being movable relative to each other, between a first configuration and a second configuration, the internal housing having a different shape in the first configuration and the second configuration.

[0017] Thus, the present invention makes it possible to manufacture oral-dental instruments whose handle is removable, which can be assembled to the blade or separated from this blade according to the needs of the practitioner. It is thus possible to implement, with the same removable handle according to the invention, a plurality of different blades. The cost of manufacturing blades without handles being lower than the cost of manufacturing instruments composed of a blade and a handle, the implementation of the invention makes it possible to reduce the cost price of oral-dental instruments.

[0018] Such a removable handle constitutes, according to the present invention, the handle of the endodontic instrument, which can, when assembled to the blade, be inserted and locked into an instrument-holding device or removed from the instrument-holding device, with the blade that it carries. It is therefore clearly distinguished from a mandrel of an instrument-holding device, which is an integral part of this instrument-holding device and is not intended to be removed from this instrument-holding device.

[0019] In the handle according to the invention, the movable elements, which are movable between a first configuration, called the closed configuration, and a second configuration, called the open configuration, and vice versa, make it possible to hold a blade in the internal housing, in the first configuration, and to release the blade, in the second configuration.

[0020] Advantageously, the movable elements of the handle are closer to the longitudinal axis in the first configuration than in the second configuration.

[0021] Thus, when the handle is in its first configuration, the movable elements can block an oral instrument blade in the internal housing located between the movable elements. On the contrary, when the handle is in its second configuration, it allows the introduction of such a blade or its removal.

[0022] According to an advantageous embodiment, the handle comprises restraining means movable between a position, called locking, in which they maintain the movable elements in a first configuration, and a position called unlocking, in which they do not maintain the movable elements in this first configuration.

[0023] These mobile restraint means allow, when in their locking position, to maintain the mobile elements in their first configuration, thus preventing the removal of a blade blocked in this internal housing.

[0024] A handle according to the invention equipped with such retention means can be held in an instrument-holder equipment head, even while a blade is inserted into the handle or removed from the handle, provided that means are available capable of moving the retention means from their locked position to their unlocked position, and vice versa.

[0025] Preferably, the handle comprises an assembly portion, close to the first end, and at least two tabs constituting the movable elements, fixed to the assembly portion and extending to their free end forming the second end of the handle, the internal housing being formed between the tabs.

[0026] According to an advantageous embodiment, these legs can extend substantially parallel to the longitudinal axis.

[0027] Advantageously, the handle includes three legs.

[0028] These legs can advantageously be distributed angularly around the internal housing, to ensure optimal support as well as centering of the blade between the legs of the handle when these are in their first configuration.

[0029] Advantageously, the legs are connected to the assembly portion by means of flexible hinges.

[0030] These flexible hinges connecting the legs to the assembly portion have a weakened section promoting the mobility of each leg relative to the assembly portion.

[0031] According to an advantageous embodiment, the movable elements of the handle, which are preferably tabs, each have an internal surface, surrounding the internal housing, this internal surface having a holding portion which is substantially planar and parallel to the longitudinal axis, when the movable elements are in the first configuration, the holding portions of each of the movable elements being located at the same distance from the longitudinal axis, when the movable elements are in their first configuration.

[0032] Thus, in the first configuration, or closed configuration of the legs, the holding portions form the portions of the sides of an equilateral triangle centered on the longitudinal axis of the handle. These holding portions can thus ensure the centering of the blade in the internal housing of the handle, such that once the handle and the blade are assembled and the legs are in their closed configuration, the longitudinal axis of the blade and the longitudinal axis of the handle merge.

[0033] Preferably, each of the holding portions of this handle constitutes the portion of the internal surface closest to the longitudinal axis, when the movable elements are in the first configuration, and is bordered by at least one shoulder defined on the internal surface, oriented towards the first end of the handle.

[0034] The holding portions thus form projections on the internal surfaces of the legs, which can thus cooperate with corresponding flats provided on the blade, in order to center this blade and prevent its removal from the internal housing of the handle.

[0035] According to a particular embodiment, each of the holding portions is bordered by at least two shoulders defined on the internal surface, one of the shoulders being oriented towards the first end of the handle, and a second of the shoulders being oriented towards the second end of the handle.

[0036] The shapes of the internal surfaces of the moving elements thus make it possible to block any translation, along the longitudinal axis, of a blade having an appropriate shape.

[0037] Preferably, the handle has an external shape which, in the first configuration, partially matches the shape of a cylindrical envelope whose axis constitutes the longitudinal axis of the handle, the entire handle being included in this cylindrical envelope.

[0038] This handle can thus have a shape compatible with the heads of instrument holders designed to receive handles of oral-dental instruments of the prior art.

[0039] In this case, according to an advantageous embodiment, the mobile elements each have an external surface, constituting a part of the external surface of the handle, at least a part of this external surface of the mobile elements having the shape of the cylindrical envelope, when the mobile elements are in their first configuration.

[0040] Advantageously, in this case, the moving elements partially protrude from the cylindrical envelope, when the moving elements are in their second configuration.

[0041] Thus, when the handle is inserted into the cylindrical opening of an instrument-holder equipment head, the diameter of which corresponds to that of the cylindrical casing of the handle, this cylindrical opening can come into contact with the external surface of the moving elements and maintain them in their first configuration, preventing their movements towards their second configuration.

[0042] Preferably, the external shape of the handle has at least one peripheral groove centered on the longitudinal axis, and at least one flat parallel to this longitudinal axis.

[0043] This handle thus has the characteristics known for standardized handles known as “Type 1”, allowing such handles to be held reversibly in a head of an instrument-carrying device, and driven in rotation by this head of an instrument-carrying device.

[0044] The present invention also relates to an oral-dental instrument, comprising a handle as described above and a blade, a portion of which is introduced into the internal housing of the handle, the movable elements and this portion of the blade having shapes such that the movable elements maintain the portion of the blade in the internal housing when they are in their first configuration, called the closed configuration, and allow the blade to be removed from the internal housing, when they are in their second configuration, called the open configuration. List of figures

[0045] The invention will be better understood upon reading the following description of preferred embodiments, given as a simple figurative and non-limiting example, and accompanied by the figures among which:is a perspective view of an endodontic instrument handle according to an embodiment of the invention.is a side view of the handle of the.is a sectional view of the handle of the, along a plane passing through its longitudinal axis.is a front view of the handle of the.is a cross-sectional view of the handle of the.is another cross-sectional view of the handle of the.is another cross-sectional view of the handle of the.is another cross-sectional view of the handle of the.is a side view of the non-active portion of the blade of an endodontic instrument according to an embodiment of the invention.is a cross-sectional view of the blade of the.lais a perspective view of a decoupling tool adapted to detach a blade from a handle according to one embodiment of the invention.lais a sectional view of the decoupling tool of the, into which an endodontic instrument is introduced.lais a perspective view of an endodontic instrument handle according to another embodiment of the invention, in an open configuration.lais a perspective view of the endodontic instrument handle of the, in a closed configuration.lais a perspective view of an endodontic instrument handle according to another embodiment of the invention, in an open configuration.lais a perspective view of the endodontic instrument handle of the, in a closed configuration.lais a sectional view of the handle of thein a closed configuration, along a plane passing through its longitudinal axis.lais a perspective view of an endodontic instrument blade according to one embodiment of the invention.lais a perspective view of an endodontic instrument blade according to another embodiment of the invention.lais a perspective view of the endodontic instrument blade of la, placed in a sheath.lais a perspective view of the endodontic instrument handle of la, into which the endodontic instrument blade placed in a sheath of la is inserted.lais a perspective view of the endodontic instrument handle of la, assembled to the endodontic instrument blade of la.Detailed description of an embodiment of the invention.

[0046] The following description of an oral instrument composed of a handle and a blade relates more specifically to an endodontic instrument. The teaching of this description can be easily transposed by a person skilled in the art to other oral instruments. In particular, the handles described below can easily be associated with blades allowing them to form non-endodontic oral instruments.

[0047] An endodontic instrument is typically composed of a blade mounted in a handle, this handle being intended to be held in the head of an instrument-holding device. In many cases, this handle, designated as "Type 1", has a standardized shape and dimensions to be introduced and held effectively in the head of the instrument-holding device.

[0048] The figure represents in perspective a handle 1 for an endodontic instrument, according to an embodiment of the invention. Conventionally, this handle 1 has an external shape making it suitable for being removably held by an instrument-holding device and driven in rotation by this instrument-holding device. More precisely, in its configuration represented by the figure, this handle 1 is included in a cylindrical envelope, and a part of its external shape matches the shape of this cylindrical envelope. The dimensions of this cylindrical envelope are advantageously those proposed by the standards defining so-called "Type 1" handles. The axis of this cylindrical envelope is designated hereinafter as the longitudinal axis 100 of the handle 1, and, more generally, as the longitudinal axis of the endodontic instrument comprising this handle 1. It corresponds to the axis of rotation of the instrument, when the latter is driven in rotation by the head of the instrument-holding device.

[0049] This handle 1 has a generally elongated shape along the longitudinal axis 100, having a first end 11, intended to form one of the ends of the endodontic instrument. Near this first end 11, the handle 1 has a generally cylindrical assembly portion 110, in which a flat 111 and a peripheral groove 112 are formed. The shape of this assembly portion 110 corresponds to that of the standardized “Type 1” handles, allowing the handle 1 to be secured and held effectively in the head of an instrument-holder equipment designed to receive such standardized handles.

[0050] At its second end 12, opposite its first end 11, the handle 1 has an internal housing 120 intended to receive the non-active portion of a blade of an endodontic instrument. According to the invention, this internal housing 120 is surrounded by several elements of the handle 1, which are movable relative to each other.

[0051] In the embodiment shown, the portion of the handle 1 which surrounds the internal housing 120 is formed by three distinct and identical tabs 2. These tabs 2 form the movable elements of the handle 1. Each of these three tabs 2 is secured, by one of its ends, to the assembly portion 110 of the handle 1. From this assembly portion 110, each of the three tabs 2 extends substantially parallel to the longitudinal axis 100 of the handle 1, to its free end, at the second end 12 of the handle 1.

[0052] Each of these tabs 2 has an external surface 21, forming a continuation of the cylindrical external shape of the assembly portion 110. Each of these tabs 2 also has an internal surface 22 surrounding the internal housing 120, and forming the surface of this internal housing 120. This internal surface 22 has a variable shape along the tab 2, from the assembly portion 110 to the second end 12 of the instrument. This shape of the internal surface 22 is described below, in connection with the sectional views of FIGS. 3 to 8.

[0053] A first cross-sectional view BB of the handle 1, close to the assembly portion 110, is represented by 1a. At the level of this first cross-sectional view, each of the legs 2 advantageously has a reduced section compared to the neighboring portions of the leg 2, and therefore a lower moment of inertia, so as to form a flexible hinge 226. The handle 1 being advantageously made of a material having great elasticity, such as for example a nickel-titanium alloy, the legs 2 can deform elastically, in particular at the level of the flexible hinges 226, in order to be movable relative to each other.

[0054] La represents a second cross-sectional view CC of the handle 1, further from the assembly portion 110 than the first cross-sectional view BB represented by la. At the level of this second cross-sectional view, the internal surfaces 22 of each of the three legs 2 form a first surface portion 224, substantially planar and parallel to the longitudinal axis 100 of the handle 1.

[0055] La represents a third cross-sectional view DD of the handle 1, further from the assembly portion 110 than the second cross-sectional view CC represented by la. At this third cross-sectional view, the internal surfaces 22 of each of the three legs 2 form a second surface portion, also called the holding portion 222, which is substantially planar and parallel to the longitudinal axis 100, and closer to the longitudinal axis 100 than the first surface portions 224. These holding portions 222 of the three legs 2 are advantageously arranged in such a way that together they form portions of the sides of an equilateral triangle centered on the longitudinal axis 100 of the handle 1.

[0056] The holding portion 222 and the first surface portion 224 are connected to each other by a shoulder 225. This shoulder 225 is a portion of the internal surface 22 which can provide support for blocking a movement along the longitudinal axis 100. In this embodiment, the shoulder 225 extends substantially in a plane perpendicular to the longitudinal axis 100 and is oriented towards the first end 11 of the handle 1. It therefore makes it possible to provide support for a component inserted in the internal housing 120 coming into contact with the shoulder 225, this support blocking the translation of this component along the longitudinal axis 100 towards the second end 12 of the handle 1.

[0057] It should be noted that, in certain embodiments, such a shoulder may have an angle relative to the perpendicular to the longitudinal axis 100, for example to form a chamfer. Thus, any surface portion making it possible to provide a support capable of blocking a translation along the longitudinal axis 100 may be considered as forming a shoulder within the meaning of the present description. This is particularly the case if several complementary chamfers together make it possible to block a translation, along the longitudinal axis 100, of a component bearing on these chamfers.

[0058] A fourth cross-sectional view EE of the handle 1, further from the assembly portion 110 than the third cross-sectional view DD represented by 1a, is represented by 1a. At this fourth cross-sectional view, the internal surfaces 22 of each of the three legs 2 form a third substantially planar surface portion 221, which is parallel to the longitudinal axis 100 of the instrument, further from the longitudinal axis 100 than the holding portions 222. In addition, the third surface portions 221 of the three legs 2 are arranged in such a way that together they form portions of the sides of an equilateral triangle centered on the longitudinal axis 100 of the handle 1.

[0059] The third surface portion 221 and the holding portion 222 are connected to each other by a chamfer 223. This chamfer 223 has an angle relative to the perpendicular to the longitudinal axis 100. However, when the legs 2 are held in a fixed configuration, for example in their closed configuration, the chamfers 223 of the three legs 2 can, together, form a support making it possible to block the translation, along the longitudinal axis 100 and towards the first end 11 of the handle 1, of a component bearing on these chamfers 223. Under these conditions, these chamfers 223 can form a shoulder, within the meaning of the present description.

[0060] At the free end of the legs 2, furthest from the assembly portion 110, which forms the second end 12 of the handle 1, each of these third surface portions 221 ends with a chamfer 2210, widening the entrance to the internal housing 120.

[0061] In the embodiment represented by the, when the legs 2 are in their rest position, in which they are not deformed, they are in their closed configuration represented by figures 1 to 8, in which their external surfaces 21 fit into the same cylindrical envelope as the assembly portion 110 of the handle 1. It is then considered that the handle 1 is in a first configuration called “closed configuration”.

[0062] The three legs 2 of the handle 1 are separated from each other by slots extending longitudinally on the handle 1. According to an advantageous embodiment, these slots are formed by cutting using an electroerosion wire, extending in a plane transverse to the longitudinal axis 100 of the handle 1, which is moved relative to the handle 1 in order to form the internal surfaces 22 of each of the legs 2. Consequently, when the legs 2 are in their rest position, all the portions of the internal surfaces 22 of the legs 2 have at least one generatrix constituted by a straight line not colliding with another surface of the handle 1.

[0063] In the embodiment shown, the slots separating the three legs 22 are substantially rectilinear, and parallel to the longitudinal axis 100. It is however possible, in other embodiments, for these slots to have different shapes, for example helical slots centered on the longitudinal axis 100.

[0064] To form the flexible hinge portion 226, the EDM wire which is used to cut the internal surfaces 22 of the legs 2 can be moved, in a plane transverse to the longitudinal axis 100 of the handle 1, in order to make the cuts locally reducing the cross-section of the legs 2.

[0065] The handle 1 is designed to be assembled to a specially adapted oral instrument blade, such as for example the blade 3 shown by the. This blade 3 has an assembly end 31, forming the end of its non-active portion 35, and a free end 37, forming the end of its active portion 36. It should be noted that the term "blade", within the meaning of the present description, is not limited to a cutting tool, but includes all tools for carrying out work on or in the teeth or the patient's mouth. The blade, within the meaning of the present description, can thus, in a non-limiting manner, have the shape of a needle, a file, a drill, a bur, a brush, etc.

[0066] In the blade 3 represented by 1a, which is intended to form an endodontic instrument, the active portion 36 is the part of the instrument which extends from its free end 37 and which is intended to be introduced into the root canal of a tooth, in order to carry out work or cleaning there. This active portion 36 thus has a specific shape, generally obtained by machining, which allows it to carry out the necessary work inside this root canal. In 1a, this active portion 36 is represented schematically by a cone. It is however common for such an active portion of an endodontic instrument to have a helical shape, fitting into a cone. Those skilled in the art will of course be able to produce the blade 3, or an equivalent blade, with an active portion having any known shape.

[0067] The non-active portion 35 is a portion of the blade 3 intended to connect the blade 3 to the handle 1. This non-active portion 35 is inscribed in the cylindrical shape of the bar in which the blade 3 is machined. The axis of this cylindrical shape is subsequently designated as the longitudinal axis 300 of the blade 3, which corresponds, when the blade 3 is assembled to the handle 1, to the longitudinal axis 100 of the handle 1, and more generally to the longitudinal axis of the instrument formed by this handle 1 and this blade 3.

[0068] This non-active portion 35 of the blade 3 is shown in detail by la and in cross-sectional view along the section plane FF by la. Near its assembly end 31, this non-active portion 35 first has a short end segment 32, having three main flat surfaces parallel to the longitudinal axis 300, positioned in such a way that the cross-section of this end segment 32 is inscribed in an equilateral triangle centered on the longitudinal axis 300 of the blade 3. At the assembly end 31, this end segment 32 advantageously ends with chamfers 310 approaching the longitudinal axis 300.

[0069] Next to this end segment 32, the non-active portion 35 has a holding segment 33, around which three flats 34 are distributed. These flats 34 preferably form flat surfaces parallel to the longitudinal axis 300, positioned in such a way that the cross-section of this holding segment 33, which is visible in the sectional view of the, is inscribed in an equilateral triangle centered on the longitudinal axis 300 of the blade 3.

[0070] These flats 34 are advantageously closer to the longitudinal axis 300 of the blade 3 than the main flat surfaces of the end segment 32, such that shoulders 341 appear at the junction between the flats 34 and the end segment 32. These shoulders 341 are parts of the surface of the blade 3 which can provide support making it possible to block a movement of the blade 3 along its longitudinal axis 300. They are advantageously oriented towards the free end 37 of the blade 3, and can extend in a plane substantially perpendicular to the longitudinal axis 300. It is however possible for these shoulders 341 to be inclined relative to a plane substantially perpendicular to the longitudinal axis 300.

[0071] The three flats 34 of the holding segment 33 advantageously have dimensions and a shape complementary to the three holding portions 222 of the legs 2 of the handle 1, such that they can come into contact with, respectively, the three holding portions 222 of the legs 2 of the handle 1, when the non-active portion 35 of the blade 3 is inserted into the internal housing 120 and the legs 2 are in their closed configuration.

[0072] Thus, in this configuration, the three holding portions 222, the cross-section of which is inscribed in an equilateral triangle centered on the longitudinal axis 100 of the handle 1, are in contact with the three flats 34 the cross-section of which is inscribed in an equilateral triangle of the same dimension, centered on the longitudinal axis 300 of the blade 3. This contact between the holding portions 222 and the flats 34 therefore ensures the centering of the blade 3 relative to the handle 1, by making the longitudinal axis 300 of the blade 3 correspond to the longitudinal axis 100 of the handle 1.

[0073] Furthermore, when the holding portions 222 are in contact with the flats 34, the shoulders 225 joining the holding portions 222 to the first surface portions 224 can come into contact with the shoulders 341 joining the flats 34 to the end segment 32. Such contact has the effect of blocking the translation of the blade 3 relative to the handle 1, along the longitudinal axis 100, in a direction tending to cause the blade 3 to exit the handle 1.

[0074] Finally, the end segment 32 of the blade 3 has dimensions allowing it to be held between the first surface portions 224 of the legs 2, when the holding portions 222 are in contact with the flats 34 and the shoulders 225 are in contact with the shoulders 341. In the embodiment shown, the length of the end segment 32 is advantageously chosen so that, in this situation, the assembly end 31 of the blade 3 comes into contact with the assembly portion 110 of the handle 1, between the flexible hinges 226. Such contact blocks any translation of the blade 3 relative to the handle 1, along the longitudinal axis 100, in a direction tending to bring the blade 3 closer to the handle 1.

[0075] The respective shapes of the non-active portion 35 of the blade 3 and of the internal surface 22 of the legs 2 of the handle 1, in the closed configuration of this handle 1, therefore make it possible to ensure that the blade 3 is secured to the handle 1. The blade 3, inserted into a handle according to one embodiment of the invention, is thus represented by the.

[0076] It should be noted that, in other embodiments, it is possible to block the translation of the blade 3 relative to the handle 1, along the longitudinal axis 100, in a direction tending to bring the handle 1 closer to the blade 3 by other means, for example by the cooperation of shoulders formed on the blade 3 and on the internal surface 22 of the legs 2.

[0077] La represents another example of an endodontic instrument blade that can be held in the handle 1. This blade 6 has an assembly end 61, and a free end 67. This blade 6 comprises an active portion 66 and a non-active portion 65.

[0078] This blade 6 is advantageously machined from a metal bar of larger diameter than that used to produce the blade 3. It thus has an active portion 66 which may have larger dimensions than the active portion 36 of the blade 3.

[0079] This blade 6 also comprises a non-active portion 65, extending to its assembly end 61. A segment 651 of this non-active portion 65, adjacent to the active portion 66, has the dimensions and cylindrical shape of the bar in which the blade 6 has been machined. An end segment 62 of the non-active portion 65 has undergone machining allowing it to cooperate with the shape of the internal surfaces 22 of the legs 2 of the handle 1.

[0080] This non-active portion 65 has, in the embodiment shown, a shape almost identical to the shape of the non-active portion 35 of the blade 3. It has in particular, near the assembly end 61 of the blade 6, three flats 64 having the same arrangements and dimensions as the flats 34 of the blade 3, and separated from the assembly end 61 by an end segment 62. This blade 6 can therefore be secured to the handle 1 in the same way as the blade 3.

[0081] It should be noted that, in other possible embodiments, the shape and dimensions of the non-active portion of a blade may be different, provided that this non-active portion has a shape complementary to that of the internal housing of the handle, allowing its assembly in this handle.

[0082] According to the invention, the handle 1 can be assembled, reversibly, with a suitable blade, such as the blade 3 or the blade 6, the non-active portion of the blade being inserted into the internal housing 120 of the handle 1. The following description describes the assembly of the blade 3 with the handle 1, but it can also be applied, mutatis mutandis, to the assembly of the blade 6.

[0083] Thus, the assembly end 31 of the non-active portion 35 of the blade 3 can be introduced into the internal housing 120 of the handle 1. When the end segment 32 enters the segment of the internal housing 120 which is defined by the third surface portions 221, it preferably does so without deforming the tabs 2, this segment of the internal housing 120 having sufficient dimensions to receive the end segment 32. The handle 1 then remains in its first configuration, called the “closed configuration”, represented by FIGS. 1 to 8.

[0084] On the other hand, when the end segment 32 penetrates into the segment of the internal housing 120 which is defined by the holding portions 222, this penetration is done by elastically deforming the tabs 2, in order to move the holding portions 222 away from each other, to allow the insertion of the end segment 32. This penetration is facilitated by the cooperation of the chamfers 223 of the tabs 2 and the chamfers 310 joining the end segment 32 to the assembly end 31 of the blade 3.

[0085] When the legs 2 are sufficiently far apart from each other, the handle 1 passes into a second configuration, called the “open configuration”, in which the legs 2 allow the introduction of the non-active portion 35 of the blade 3 into the internal housing 120.

[0086] When the end segment 32 continues its penetration into the internal housing 120, it passes into the segment of the internal housing 120 which is defined by the first surface portions 224. Preferably, this segment of the internal housing 120 has sufficient dimensions to accommodate the end segment 32 without the legs 2 being deformed.

[0087] When the end segment 32 has completely penetrated into the segment of the internal housing 120 which is defined by the first surface portions 224, the flats 34 are in the segment of the internal housing 120 which is formed by the holding portions 222 of the tabs 2. At this moment, the tabs 2 which have been elastically deformed, to put the handle 1 in its open configuration, can resume, under the effect of elastic return, their rest position corresponding to the first configuration, called “closed configuration”, of the handle 1. The holding portions 222 then come into contact with the surfaces of the flats 34, if necessary by slightly rotating the blade 3 around its longitudinal axis 300, in order to ensure the alignment of the surfaces coming into contact.

[0088] At this moment, the non-active portion 35 of the blade 3 is locked in the handle 1 which is returned to its closed configuration. Indeed, the shoulders 225 of the handle 1, having come into contact with the shoulders 341 joining the flats 34 to the end segment 32 of the blade 3, prevent the removal of the blade 3 from the handle 1 as long as this handle 1 is in its closed configuration, in which the tabs 2 are not elastically deformed.

[0089] If the handle 1 is then inserted into a cylindrical opening, such as the opening of an instrument-holder equipment head, deformation of the legs 2 to their open configuration then becomes impossible. The handle 1 is then forced to remain in its closed configuration, and the blade 3 cannot be removed from the handle 1 while the handle 1 is in this opening.

[0090] When the non-active portion 35 of the blade 3 is locked in the handle 1, and the deformation of the tabs 2 is not prevented, it is possible to detach the blade 3 from the handle 1 by rotating the blade 3 by one-sixth of a turn, around its longitudinal axis 300, relative to the handle 1. Such a rotation has the effect of bringing the holding portions 222 into contact with the cylindrical envelope of the holding segment 33 of the non-active portion 35 of the blade 3 which is located between the flats 34. The diameter of this cylindrical envelope being equal to the diameter of the envelope of the end segment 32, the holding portions 222 are moved away from each other, elastically deforming the tabs 2. The handle 1 then passes into its open configuration. It is then possible to remove the non-active portion 35 of the blade 3 from the internal housing 120 of the handle 1, by sliding it along its longitudinal axis 300.

[0091] In the embodiments in which the shoulders 225 form chamfers, it is also possible to detach the blade 3 from the handle 1 by simply exerting traction on this blade 3, in the direction of the longitudinal axis 300. The cooperation of the chamfers then has the effect of deforming the legs 2 until they pass into their open configuration, and the blade 3 can be removed from the handle 1.

[0092] It is also possible, according to a variant, to detach the blade 3 from the handle 1 using a specific detaching instrument. Figures 11 and 12 show, by way of example, such a detaching instrument 4 according to a possible embodiment.

[0093] This detaching instrument 4 is presented as a housing forming an internal chamber 41, intended to collect the blade 3 after its detachment. In the embodiment shown, this internal chamber 41 is open, which allows access to the blades contained therein.

[0094] The detaching instrument 4 has a slot 42 allowing the active portion 36 of the blade 3 to be easily introduced into the internal chamber 41, the handle 1 remaining outside the internal chamber 41. At one end of this slot 42, the detaching instrument 4 has a conical-shaped collar 43.

[0095] This collar 43 is positioned in such a way that a user inserting the active portion 36 of the blade 3 of an oral-dental instrument into the slot 42, as shown in 1a, can, by pressing the blade 3 against the edge of the slot 42, bring the handle 1 into contact with this collar 43. As shown in 1a, the shape of the collar 43 is chosen so as to cooperate with the chamfers 2210 of the legs 2 of the handle 1. Pressure on the handle 1 in the direction of the detaching instrument 4 causes the chamfers 2210 to press against this collar 43, having the effect of moving the legs 2 apart from each other, and therefore of moving the handle 1 into its open configuration. The blade 3 is then no longer held by the legs 2, and it can fall by gravity into the internal chamber 41.

[0096] Of course, a person skilled in the art can easily produce numerous variants of such a detaching instrument 4, making it easier to detach the handle 1 and the blade 3.

[0097] The handle 1 according to the invention can therefore be secured to a suitable oral-dental instrument blade, in a reversible manner. The same handle 1 can therefore be used several times, to receive a plurality of oral-dental instrument blades, for example endodontic ones, which can be single-use.

[0098] Such a handle 1 has great advantages over prior art handles assembled in a non-removable manner to the blade of the instrument. Thus, in the solution of the invention, the manufacturer of oral-dental instruments can provide the dental practitioner with a single handle to accompany a series of blades. When he needs to change the blade, the dental practitioner can remove the used blade from the handle and put a new blade in it. Since the cost of manufacturing a blade, without its handle, is lower than the cost of manufacturing a blade equipped with a fixed handle, such a solution makes it possible to reduce the overall cost borne by the practitioner.

[0099] Furthermore, since the handle 1 has the same external shape as the standardized handles of the prior art, it remains compatible with the instrument-carrying equipment of the prior art.

[0100] Figures 13 and 14 show a handle 5 according to another possible embodiment of the invention. Like the handle 1 described previously, this handle 5 has, near a first end 51, an assembly portion 510, in which a flat 511 and a peripheral groove 512 are formed. The shape of this assembly portion 510 corresponds to that of the standardized handles of endodontic instruments, allowing the attachment of this handle 5 in the head of an instrument-holding device of the prior art adapted to hold a standardized handle of “Type 1”.

[0101] Moving away from this first end 51, the handle 5 has a cylindrical intermediate portion 53, with a diameter smaller than the diameter of the assembly portion 510. This intermediate portion 53 is extended, up to the second end 56 of the handle 5, by three tabs 52 extending substantially in the direction of the longitudinal axis 500 of the handle 5. These three tabs 52 advantageously have internal surfaces 521 similar to the internal surfaces 22 of the tabs 2 of the handle 1, and of the same dimensions. On the other hand, in the closed configuration of the handle 5 represented by 1a, the external surfaces 525 of these tabs 52 are in line with the cylindrical external shape of the intermediate portion 53.

[0102] A coil spring 54, shown in Figures 13 and 14, is mounted around the intermediate portion 53. When this coil spring 54 is at rest, as shown in 1a, it surrounds both the intermediate portion 53 and the legs 52. It can also be compressed, on the intermediate portion 53, as shown in 1a.

[0103] In the embodiment shown in Figures 13 and 14, the end of the helical spring 54 furthest from the first end 51 of the handle 5 is secured to a ring 55 surrounding the intermediate portion 53 or the legs 52. Means for preventing the helical spring 54 and the ring 55 from being removed from the handle 5 can be implemented by those skilled in the art, but they are not further described in the present application.

[0104] When the helical spring 54 is at rest as shown in 1a, the ring 55 is in a position called the “locking position”, in which it surrounds the legs 52. This ring 55 then forms a retention means keeping the legs 52 relatively close to each other, in their closed configuration. In this closed configuration, the legs 52 do not allow the introduction of a blade into the internal housing 520 which they surround. On the other hand, if a suitable blade is previously placed in this internal housing 520, it is held by the legs 52 without being able to be removed.

[0105] On the contrary, when the helical spring 54 is compressed, the ring 55 is brought back around the intermediate portion 53, as shown in 1a, into a position called the “unlocking position” in which it no longer grips the tabs 52, and no longer holds them in their closed configuration.

[0106] These legs 52 can then move apart from each other, as shown in . This spacing can be adopted naturally by the legs 52, if the flexible hinges which connect them to the intermediate portion 53 are shaped so as to move them apart from each other by elasticity. Otherwise, this spacing can be obtained by the introduction of an object into the internal housing 520 between the legs 52. When the legs 52 are thus separated, they allow the introduction of the non-active portion of a blade such as the blade 3 into the internal housing 520, or the removal of a blade previously placed in this internal housing 520.

[0107] The ring 55 and the spring 54 thus form mobile retention means between a locking position, in which they maintain the tabs 52 in their closed configuration, and an unlocking position, in which they do not maintain these tabs 52 in their closed configuration.

[0108] The handle 5 can therefore be assembled, reversibly, to a suitable oral-dental instrument blade. Once the blade is assembled to this handle 5, the handle 5 can be inserted into the head of an instrument-holding device, and held there and rotated in the same way as a standardized oral-dental instrument handle. For this, the dimensions of the helical spring 54 and the ring 55 are such that they do not protrude from the cylindrical envelope of the assembly portion 510, the diameter of which corresponds to that of the standardized handles.

[0109] Figures 15 to 17 represent a handle 8 according to a variant of the embodiment represented by figures 13 and 14. This handle 8 has an assembly portion 810 and an intermediate portion 83 similar, respectively, to the assembly portion 510 and to the intermediate portion 53 of the handle 5. It also has three tabs 82, extending the intermediate portion 83.

[0110] The internal surfaces 821 of these tabs 82, although of slightly different shapes from the internal surfaces 521 of the tabs 52, also have shapes capable of holding a suitable blade inserted between the tabs 82 of the handle 8, when these tabs 82 are in a closed configuration, in which they are relatively close to each other. On the contrary, these shapes of the internal surface 821 make it possible to introduce such a blade between the tabs 82, or on the contrary to remove it, when these tabs 82 are in an open configuration in which they are further apart from each other. Each of these internal surfaces 821 has in particular a holding portion 824 which is substantially planar and parallel to the longitudinal axis 800 of the handle 8, and at the same distance from this longitudinal axis 800, when the tabs 82 are in their closed configuration, in order to ensure the centering of a blade.

[0111] The external surface 822 of the legs 82 extends in continuity with the external shape of the intermediate portion 83, up to a stop 823 which forms the external surface 822 of the legs 82 near the free end of these legs 82. A helical spring 84 surrounds the intermediate portion 83 and the external surface 822 of the legs 82, up to the stops 823. When this helical spring 84 is relaxed, in its position called the “locking position” shown in FIGS. 16 and 17, it bears on the assembly portion 810, on one side, and on the stops 823, on the other side. The dimensions of the helical spring 84, and in particular its internal diameter, and the shape and dimensions of the external surface 822 of the legs 82 near the stops 823 are such that, when the helical spring 84 is in this relaxed position, its turns bearing against the stops 823 surround the external surfaces 822 of the legs 82 while maintaining these legs 82 in their closed configuration.

[0112] The helical spring 84 can also be compressed, as shown in 1a, into a position called the “unlocking position” in which it only partially surrounds the legs 82 and is no longer in abutment against the stops 823. The shape of the external surfaces 822 of the legs 82 is such that, in this unlocking position of the helical spring 84, this helical spring 84 no longer maintains the legs 82 in their closed configuration but, on the contrary, allows them to move slightly away from each other, into their open configuration shown in 1a.

[0113] The helical spring 84 thus forms a movable restraining means between a locking position, represented by 1a, in which it maintains the legs 82 in their closed configuration, and an unlocking position, represented by 1a, in which it does not maintain the legs 82 in their closed configuration. In the embodiment represented by these figures, the legs 82 are advantageously in a rest position when they are in their open configuration, and are elastically deformed to move to their closed configuration. Thus, when the helical spring 84 moves into its unlocking position, these legs 82 can move, without further intervention, into their open configuration.

[0114] According to a particularly advantageous characteristic, the handle 8 can have dimensions such that, when the tabs 82 are in their open configuration, the external diameter of the handle 8, and in particular of its end formed by the stops 823, does not exceed the diameter of the assembly portion 810, corresponding to the diameter of the standardized handles of “Type 1”. Thus, the handle 8 can pass from its closed configuration, with the helical spring 84 in its locked position, as shown in 1a, to its open configuration, with the helical spring 84 in its unlocked position, as shown in 1a, and vice versa, even when it is inserted and secured in the head of an instrument-holder equipment.

[0115] In such a configuration, the handle 8 can be permanently installed in the head of an instrument-holding device, the dental instrument blades being able to be inserted or removed therefrom at will. The handle 8 can then, in such a configuration, serve as an adapter making it possible to hold, in an instrument-holding device designed to hold and drive a handle with standardized “Type 1” dimensions, an instrument or an instrument blade not having such a handle, and on the contrary having a non-active portion whose dimensions are smaller than the dimensions of the standardized handle.

[0116] The introduction of a blade into the handle 8, or the removal of a blade from this handle 8 requires pushing the helical spring 84 towards the intermediate portion 83, which is difficult to implement without suitable equipment, particularly when the handle 8 is introduced into a head of an instrument-holding device. To facilitate this manipulation, the blade which must be introduced into the handle 8 can advantageously be equipped with a specific sheath, allowing the retention means of the handle 8 to pass into their unlocking position. L thus represents, by way of example, the blade 3 inserted into such a sheath 7.

[0117] This sheath 7 advantageously has a case 71 surrounding the active portion 36 of the blade 3. This case 71, of tubular shape, can be made of a relatively flexible plastic and can be open, near the tip of the active portion 36 of the blade 3, or on the contrary be closed, for example in order to keep this active portion 36 sterile. At its end closest to the assembly end 31 of the blade 3, the sheath 7 forms a rigid crown having three fingers 72, which extend along the non-active portion 35 of the blade 3, in a direction parallel to the longitudinal axis 300 of this blade 3, in the direction of its assembly end 31.

[0118] The dimensions and shape of these fingers 72 are chosen so as to allow their introduction into the slots located between the tabs 82 of the handle 8, when the non-active portion 35 of the blade 3 is introduced into the internal housing 820 located between these tabs 82. This introduction into the handle 8 of a blade 3, surrounded by a sheath 7, is represented by la. During this introduction, the fingers 72 push the helical spring 84 towards the intermediate portion 83 of the handle 8. These three fingers 72 thus make it possible to move the handle 8 from its closed configuration represented by fig. 16 to its open configuration represented by la, together with the introduction of the blade 3 into this handle 8.

[0119] Once the non-active portion 35 of the blade 3 is inserted into the internal housing 820 of the handle 8, the sheath 7 can be removed, while maintaining the blade 3 in the handle 8. The handle 8 then returns to its closed configuration, securely maintaining the blade 3, as shown in.

[0120] The removal of the blade 3 from the handle 8 can be achieved by replacing the scabbard 7 on the blade 3, in such a way that the fingers 72 are inserted into the slots located between the tabs 82 of the handle 8, pushing back the helical spring 84. The handle 8 then returns to its open configuration, and the blade 3 can be removed from the handle 8, for example at the same time as the scabbard 7.

[0121] It should be noted that, advantageously, the insertion and removal of the blade 3 into the handle 8 can be carried out even while the handle 8 is inserted into the opening of an instrument-holder equipment head. This handle 8, inserted into an instrument-holder equipment head intended to receive oral-dental instruments comprising a handle, can thus allow this instrument-holder equipment head to receive blades of oral-dental instruments, which do not comprise an attached handle.

Claims

Handle (1, 5, 8) for an oral-dental instrument, said handle having an external shape elongated along a longitudinal axis (100, 500, 800), making it suitable for being removably held by an instrument-holding device and rotated, around said longitudinal axis, by said instrument-holding device, said handle having a first end (11, 51) and a second end (12, 56) opposite said first end, said handle having an internal housing (120, 520, 820), open at said second end and extending along said longitudinal axis, said internal housing being suitable for receiving a portion of a blade (3, 6) of said oral-dental instrument, characterized in that said handle (1, 5, 8) comprises at least two movable elements surrounding said internal housing (120, 520, 820), said movable elements being movable relative to each other the other, between a first configuration and a second configuration,said internal housing having a different shape in said first configuration and said second configuration., Handle according to the preceding claim, characterized in that said movable elements are closer to said longitudinal axis (100, 500, 800) in said first configuration than in said second configuration. Handle according to any one of the preceding claims, characterized in that it comprises restraining means movable between a so-called locking position, in which they maintain said movable elements in said first configuration and a so-called unlocking position, in which they do not maintain said movable elements in said first configuration. Handle according to any one of the preceding claims, characterized in that it comprises an assembly portion (110, 510, 810) close to said first end, and at least two tabs (2, 52, 82) constituting said movable elements, fixed to said assembly portion and extending to their free end forming said second end (12, 56) of said handle, said internal housing (120, 520, 820) being formed between said tabs. Handle according to the preceding claim, characterized in that it comprises three of said tabs (2, 52, 82). Handle according to any one of claims 4 and 5, characterized in that said tabs (2, 52, 82) are connected to said assembly portion by means of flexible hinges (226). Handle according to any one of claims 4 to 6, characterized in that said tabs (2, 52, 82) each have an internal surface (22, 521, 821), surrounding said internal housing (120, 520, 820), said internal surface having a holding portion (222, 824) substantially flat and parallel to said longitudinal axis (100, 500, 800), when said tabs are in said first configuration, said holding portions of each of said tabs being located at the same distance from said longitudinal axis, when said tabs are in said first configuration. Handle according to the preceding claim, characterized in that each of said holding portions (222, 824) constitutes the portion of said internal surface (22, 521, 821) closest to said longitudinal axis (100, 500, 800), when said tabs (2, 52, 82) are in said first configuration, and is bordered by at least one shoulder (225), defined on said internal surface, oriented towards said first end (11, 51) of said handle. Handle according to the preceding claim, characterized in that each of said holding portions (222, 824) is bordered by at least two shoulders (225, 223) defined on said internal surface, one of said shoulders (225) being oriented towards said first end (11, 51) of said handle, and a second of said shoulders (223) being oriented towards said second end (12, 56) of said handle. Handle according to any one of the preceding claims, characterized in that said handle (1, 5, 8) has an external shape which, in said first configuration, partially matches the shape of a cylindrical envelope whose axis constitutes the longitudinal axis (100, 500, 800) of said handle, the whole of said handle being included in said cylindrical envelope. Handle (1) according to the preceding claim, characterized in that said movable elements (2) each have an external surface (21), constituting a part of the external surface of said handle, at least a part of said external surface of said movable elements having the shape of said cylindrical envelope, when said movable elements are in said first configuration. Handle according to any one of claims 10 and 11, characterized in that said movable elements (2) partially protrude from said cylindrical envelope, when said movable elements are in said second configuration. Handle (1, 5, 8) according to any one of the preceding claims, characterized in that said external shape of said handle has at least one peripheral groove (112, 512) centered on said longitudinal axis (100, 500, 800), and at least one flat (111, 511) parallel to said longitudinal axis. Oral-dental instrument, comprising a handle (1, 5, 8) according to any one of the preceding claims and a blade (3, 6) a portion of which is introduced into said internal housing (120, 520, 820) of said handle, said movable elements and said portion of said blade having shapes such that said movable elements - maintain said portion of said blade (3, 6) in said internal housing when they are in said first configuration, called closed configuration, and - allow the removal of said blade (3, 6) from said internal housing, when they are in said second configuration, called open configuration.

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